iStock/Thinkstock(NEW YORK) -- The Washington, D.C., apartment where Vassilios Stassinos was found dead looked more like a pharmacy than a residence in the nation's capital.

Metropolitan Police Department officials had been called to the apartment on E Street on Jan. 26. 2009, where they found Stassinos' dead body and a trove of more than 17,000 pills.

Among the packages, which were labeled in Chinese and Urdu, were brand name prescription drugs including Xanax, Vicodin, Ritalin and Valium, according to a criminal complaint filed in U.S. District Court.

Stassinos, who had died of natural causes, was neither a pharmacist nor a physician, and further investigation of documents and computers seized from his apartment revealed he was conducting business with an alleged rogue online pharmacy titan located 7,000 miles away in Karachi, Pakistan.

The federal complaint indicated investigators believed Stassinos was distributing the drugs in the U.S.

Rogue Internet pharmacies are billion dollar illicit operations that launder their profits and put United States consumers at risk by providing substandard or counterfeit drugs, according to a report earlier this year by the U.S. Government Accountability Office.

The operation Stassinos was allegedly involved in is one of thousands of rogue online pharmacy operations located abroad and serving U.S. customers, who according to the FDA, face considerable risks by patronizing them.

The Food and Drug Administration has estimated that one in four Americans buys prescription drugs online, often from what are fake pharmacies.

"These rogue Internet pharmacies may sell drugs that are expired, improperly labeled, or are counterfeits of other drugs," the GAO report warned earlier this year.

It is a lucrative business.

"There is enough money there that people are keeping these sites in business," said Carmen Catizone, executive director of the National Association of Boards of Pharmacy, an independent group that supports the state boards of pharmacy in creating uniform regulations.

The problem of rogue online pharmacies is so pervasive that 97 percent of them are deemed dangerous for use by U.S. consumers, according to the findings outlined in the GAO report.

Baney said the large online pharmacies skirting U.S. laws each earn upwards of $1.5 to $2 million per month.

Serious efforts to police the illicit drug outlets began in 2008 when Congress passed the Ryan Haight Online Pharmacy Consumer Protection Act. Haight, 18, died seven years earlier of an overdose from painkillers he procured online by filling out a simple questionnaire.

But efforts to crack down on the fake pharmacies clearly have not halted them.

In March, nine people were forced to forfeit more than $94 million in proceeds connected to a rogue online pharmacy.

Also that month, two Rhode Island men admitted in court they participated in a scheme to repackage drugs and sell them over the internet. A portion of the illegal drug profits was then laundered to associates in Israel, according to the Department of Justice.

Baney said that although these crackdowns represent progress, there is still plenty more illicit businesses that aren't being detected.

The GAO noted the difficulty in criminally prosecuting the illegal sites. "Piecing together rogue Internet pharmacy operations can be difficult because they may be composed of thousands of related websites, and operators take steps to disguise their identities."

Baney concedes that one concern is that the illegitimate sites siphon off profits from responsible pharmacies, but a greater concern is that they are health threats.

An extreme example is the death of Marcia Bergerson, a Canadian resident and U.S. citizen, who died in Vancouver Island in 2006. The coroner concluded that her death was caused by a lethal prescription that was contaminated with levels of lead, titanium and arsenic, according to the Alliance for Safe Online Pharmacies, which keeps track of cases of this nature.

But often the danger is not as obvious, Baney claims. She suggests that many deaths are caused by drugs purchased from phony pharmacists, but go undetected because the deaths are blamed on underlying health problems, such as cancer or high cholesterol.

"Often people will say, 'the cholesterol got the best of him,' but they're not asking, 'is the medicine legitimate?' It's really hard to know the difference," she said.

Catizone said he and his colleagues at the National Association of Boards of Pharmacy frequently make purchases from rogue sites to establish that they are illegally selling drugs, but shutting them down isn't easy.

"To shut them down, we alert the FDA, who alerts the authorities in their country," he said. "If you look at the limited resources, this doesn't work well."

Catizone and other groups are trying to educate consumers on how to purchase from safe online pharmacies.

The NABP was recently awarded the Internet "pharmacy" domain, he said, and wants to move all legitimate online pharmacies to the domain in which all approved online drug outlets would end with a ".pharmacy," Catizone said.